Die head



g- 4, 1942- i c. A. ,REIMSCHISSEL 2,291,920

" DIE HEAD Filed July 27, '1940 4 Sheets-Sheet 1 in \L\.

I l I I l ATTORNEY Aug. 4, 194

A. REIMSCHISSEL DIE HEAD Filed July 27, 1940 4 Sheets-Sheet 2 mvam'oa I E. I v

1942- c. A. REIMSCHISSEL ,9 Q

' DIE HEAD Filed July 27, 1940 4 Sheets-Sheet 5 chasers; further, suitable camming means may be employed to reset the head automatically instead of by hand. Consequently, this feature of adaptability constitutes a further feature of my invention.

In addition to the above mentioned objectives. it has been my purpose to produce a pull-off type die head having the features of being selfsealed against the entrance of foreign matter, of being free from any possibility of entrapment of fluid which would tend to retard or otherwise interfere with the operation of the head, of utilizing a radial type latching mechanism having a circumferential bearing of relatively long life and which may be reconditioned with relative ease, and of utilizing improved type gibs adjustably mounted on the face of the head and having a sliding engagement with the chaser holder slides so that a precise fit may be maintained been my specific purpose to provide a pull-off the pull-ofl action to effect the collapsing of the Fig. 1 is a face or end view of an improved die head in accordance with the present invention, two of the chaser holders being removed to reveal details of the chaser slide coacting slide- I ways in the face of the head;

Fig. 2 is a longitudinal section on the line, 2-8 of Fig. 1 withthe parts of the head in closed thread-cutting, position;

which normally prevents unintentional or prernature head opening, and one of the camming type die head wherein the means for resetting the die head to threading position coacts with but is independent of the'latch mechanism, having non-locking camming surfaces. This evercomes a disadvantage of the structure disclosed in my United States Patent 2,082,758 wherein the meansfor effecting a resetting of the head to its thread-cutting position after ithas been tripped;

Fig.4isasectionon line'l-l of Fig.2and .showing details of the latching arrangement and of the hand opening feature;

Fig. 5 is a fragmentary view showing the out- V slideway bearing arrangement which I prefer camming faces of the resetting means are adjacent to the latching faces of the latch, which ar-- rangement eventually causes; the latching faces able latches permits having. a faster camming action to trip the head as compared with a radially functioning latching arrangement of the vtype shown in my United States Patent 2,082,758. Thus, the tripping operation can be effected more quickly, and the die head may be made slightly shorter in length.

A further specific objective has been to provide a latch mechanism incorporating radially slidable latches adapted to vbe actuated in a dual manner, the latches having camming faces that are axially and peripherally inclined to effect radial displacements thereof by either axial or peripheral camming contact with the latch actuating member. 4

A further specific objective has been to provide a means for effecting the peripheral movement to reset the die head or to cause the peripheral camming of the latches, having integral to employ, the chaser holders being shown in elevation.

Referring specifically to Figs. 1 and 2, the die head of the present invention comprises a head body 20 having an extension 2| axially slfdable within the coacting bore 2: of the shank member 23. with an enlarged head portion 24 adapted to carry and coact with chaser holders 4| and 42, and two others not shown; similarly reduced portion 2! of shank 23 is adapted to be received within the coacting bore of some form of threading machine such as a turret lathe. In order to prevent relative rotation between the head body and the shank, the lugs 26 are formed integral with the latter and coact with suitable recesses I! of head ent 2,082,758. I

Other objects and the nature and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

body '20. The foregoing comprises the means whereby the driving forces are transmitted to the cutter-carrying portion of the head.

In the enlarged forward portion 24 of the head body 20 are chaser holder slideways, II, If, a and It which coact, respectively, with slides on chaser holders H, 42, and on two other similar chaser holders which have been removed to show the character of the bottom slide surfaces of slideways II and N (see Fig. 1),. While the die head as herein shown utilizes four chaser holder assemblies, it is obvious that fewer or more such assemblies could be employed.

As heretofore noted, the chaser holders which I prefer to employ are in general of the types illustrated in copending applications Serial No. 249,324 and Serial No. 249,325. However, in the present instance, the slide portion of each of the holders is adapted to coact with an improved,

be discussed. Chaser holder 4| has therein a recess ll adapted toreoeivethe tangential chaser II, and it further incorporates another recess 41 Head body ll also has integral therea in which is located the chaser clamp 60. Clamp 80 coacts with clamping screw 65 to clamp the holder in intimate contact with'the bottom of chaser 50 to holder 4|; further, adjustment serrations 5I 'on chaser50, and 6| on clamp 60 are provided to interlock these two members so that they may be adjusted as a unit with respect to the holder in the manner disclosed in the said cc-pending applications Serial No. 249,324 and Serial No. 249,325. The adjustment screw I0, 10-- cated in an integral lug 48 of holder 4I,-is provided to effect longitudinal positioning of the chaser and'ciamp unit'with respect to the holder. I

Since this much of my present disclosure is entirely in accord with the disclosures of co-pending applications Serial No. 249,324 and Serial No. 249,325, it is evident that my present invention is not concerned with any new form of chaser adjustment nor with any novel chaser-holder functions. However, I do disclose an improved means for retaining the chaser slides within the die head, which arrangement will now be described. Y

The present holder assembly utilizes an improved type of holder slide die head gib arrangement, the outline of which can bestbe seen-in Fig. 8. The base surface 6| of the slide portion of the holder 4| is in intimate contact with slideway surface 82 of the respective slideway; =and holder slide surfaces 84 and 85 are likewise in similar contact with slideway surfaces 66 and 81, respectively. These latter mentioned surfaces are preferably normal to the first mentioned-surfaces. To retain the holder'sli'de within its slideway, the gib 9| is located within a recess 96 in the forward portion 24 of die head body 20 and 'itssiideway, which wear compensating arrangeploying dovetails regardless of whether they are,-

gibbed or not. Likewise, since my present are, rangement dispenses with the T-shaped gibs utilized in copending application 8. N. 268,966, it is possible for meto apply it to small sizes of die "heads which have insufficient face surface area to receive these larger and more complicated type gibs, which are inherently more expensive to produes and which are in no way superior to my present gibs.

Each of the holders'is prongs I21, which form integral partsof the is so designed that the forward portion I00 thereof has its bottom surface IOI in intimate contact with holder slide-surface I06. Similar gibs 92, 93, and 84 are provided for the slides of the respective other holder assemblies. employed in this die head; likewise, similar gib recesses 61. S8 and 99 are provided to coact with these respective gibs. These gib recesses are so proporclosing ring I80 that is slidably mounted onthe' -die head body 20. Forward movement of the closing ring I30 causes the chaser holders to be displaced radially inward by the camming contact provided by therespective closing ring prongs.

radially outward andthereby releases the chasers from the work. The manner in which the clos- 'ing ring cooperates with the head body to so actuate the chaser holders is more fully described in my. said prior die head disclosures of U. S. Patents No. 2,082,757 and No. 2,082,758.

tioned that the top surface of each of the respective gibs resting therein does not extend beyond the face of the die head even when several l thicknesses of shim stock (not shown) are inserted between the gib and the bottom of its respective die head recess. Thus, in addition to providing a means for taking up the wear to which the bottom surfaces of the gibs are subjected, this arrangement assures having'a flush 'die head face surface IIO, which preferably is offset by a slight clearance (not visible) from the under surfaces II I of each of the holders so'that they are supported entirely by the respective slideways. Each of the gibs 'is fastened to the die head by fillister head screws I I5 and is so designed that the gibsurface I20 does not bear 'against the holder slide. The slight clearance-- which does exist between these surfaces is not visible due to the scale of the drawings.

As has previously been stated, mypresent holder slide gibbing arrangement is basically similar to that disclosed in co-pending die head application Serial No. 268,966; consequently, it incorporates the many advantages thereof overones such as those disclosed in my U. S. Patent No. 1,951,290 and in co-pending applications Serial No. 249,324 and Serial No. 249,325. It should be noted that the L-shaped slide is much easier o machine accurately than the dovetail type and that inherently it is better adapted to withstand longitudinal cutting thrusts. .The use of adjust able gibs makes it possibleto hold the chase:-

3, 5 and 6, opening springs I35 are disposed in bores pro- Referring more particularly to Figs. 2,

vided in the forward portion of the head body 20 and in the closing ring I30. When' the die head is in its closed orthreading position, the com- Y bined force ofthese'springs serves to press end surface I8I. of. closingring I30. against thebot tom surfaces I40 of latch members I45. I This spring force, in turn, is transmitted directly to the locking ring I60, each latch member having a surface I bearing directly against the said locking ring I50. To oppose this rearward force acting on locking ring I50, an adjusting ring I is adjustably connectedto the head body 20 by virtue of the engagement of its threaded section I82 with the threaded portion I68 of said head body and incorporates'an overhanging flange I6I which coacts with a shoulder III on locking ring' I50. Thus, these parts form a closed'unit which henceforth will be referred to as the front or pulloff unit of the die head.

The locking means no rqrftne diametrical setting is utilized -'to prevent undesired rotation of adjusting ring I60 with respect to head body 20. This means comprises a member I86which is attached to head body 20 by screw, I61 and which carries the thumb-screw I that contacts the;

exterior peripheral surface of I60 andexerts a frictional locking eflect s'ufllcient to prevent the ring from rotating (see Fig. 7). In addition-to serving as means to adjust ably. yet positively, determine the axial displacement between I the head body and the closing ring, which na-f provided with a camming 1 means I25, located within a slot .I26 thereof.

These camming means are adapted to cooperate with coacting means on one of the respective Likewise, rearward movement of this ringcauses the chaser holders to be; displaced turally establishes the radial position or cutting diameter of the chaser holders, the adjusting ring I33 serves as an effective seal against the entrance of foreign matter into the interior of this front unit of the die head.

The rear unit of my die head is comprised of the shank member 33 and the retaining ring I'I3 which is adapted to rotate with respect to the said shank and which normally is in contact with the rear face I" of the annular shoulder I13 thereof. The locking ring I33 incorporates a plurality of bores containing pull-back springs such as the spring I33. The force ofthe spring I33 acts against the head I33 of the pin I33, which pin is adapted to be fastened to the retaining ring I13. The combined force of the pull-back springs acts to press the counterbored surface I33 of locking ring I33 against the front face I13 of annular shoulder I13 and to press the retaining ring I13 against the rear face I" thereof. Thus, these pull-backsprings comprise a resilient connecting means which normally holds the front and rear units of the die head together in firm contact.

If a certain size of thread is desired to be cut and the die head is not set for that particular sire, it is merely necessary to loosen the thumbscrew I33 and then rotate the adjusting ring I33, by placing a suitable wrench in the recessed socket I33 thereof, until the desired diametrical setting of the holders has been efiected by having the proper axial displacement between the closing ring I33 and the head body33. It should be remembered that the closing ring I33 is forced to move as far rearward as the flange I3I of adjusting ring I33 will permit it to go, for the opening springs I33 are constantly urging it rearwardly with respect to the head body 33. Thumbscrew I33 is then tightened so that no accidental relative rotation can occur between the adjusting ring and the head body.

As the chasers engage the work, the initial rearward axial thrust on the front unit of the die head is absorbed by the shoulder III of shank 33, for the locking ring I33 bears against the front face I13 thereof. After the first few threads have been formed, the chasers can serve to act as their own leadscrew, in which case, the front unit 'no longer presses against the shoulder I" but is in equilibrium with the rear unit, being restrained from moving forwardly with respect thereto by the force of the pull-back springs I33. When the desired thread length has been cut,

the relative axial movement between the die head and the work is interrupted by some form of stop (not shown). However, since the chasers still are'engaged with the work and since the relative rotation therebetween has not been interrupted, the front unit of the die head starts to pull away or separate from the rear unit thereof, meanwhile compressing the pull-back springs I33.

As the above mentioned pull-off action commences. the. latch members I33 are pressed radially outward, due to the camming contact between their inclined surfaces I33 and the peripheral latch surfaces I33 of shank member 33, meanwhile compressing the latch spring; I33 which are constantly urging the latches inward- 1!. 1111s carnmingaction continues until the bottom surfaces I33 of latch members I43 lose contact with the end surface "ii of closing ring I33 and are aligned with the annular recess I33 thereof. The opening springs I33 new force the closing ring I33 rearwardly until-its end surof locking ring I 33. This relative axial movement between thehead body 33 and -thecloshis ring I33 results in causing the chasers to be moved radially outwardly and thereby to lose their contact with the work. Consequently, the

' pull-back springs I33 draw the front unit of the die head back into contact with the shoulder To reset the die head to its original thread-- cutting position, it is necessary to axially advance the closing ring I33 forward-1y away from its contact with surface I33 of locking ring I33 so that the latch members I33 can again have their bottom surfaces I 33 in contact with end surface III of said closing ring I33. For this purpose, there is provided the cam pin 333 carried by the closing ring I33 and whose concshaped head is adapted to fit into the counter: sunk recess 333 of the locking ring I33. By .rotating the locking ring I33 relative to the closing ring I33; the camming contact between pin 333 and the coacting recess 333 serves to move the closing ring forwardly until the latch springs I33 again are free to move the latches I33 radially inwardly to their initial positions. Two of these pins and recesses are used to ensure easy operation.

wise rotation imparted to the locking ring'I33 to be assured that the closing ring I33 has travelled sufficiently forwardly to assure having the latches. I33 moveinwardly to locked position;

consequently, the necessary clockwise rotation of the locking ring I33 to permit closing ring surface "I to abut the latches will be limited finally only by the camming resistance between latch surface I33 and surface I33 of the shank.

Excessive clockwise rotation of locking ring I33- will open the head, but before any opening action occurs, the pin 333 and socket 333 will have lost all contact. Therefore, the pin 333 and socket 333 need not necessarily be in contact when the head is in cutting condition, in fact, a slight clearance therebetween is more generally the case than the contact shown in Fig. 4.

Consequently, when the head is in lockedcondition. the pin 333 and socket 333 serve no-useful face I3I is in contact with the front surface I33 ly await manual counter-clockwise rotation of locking ring I33 to effect their only function: that of separating the rings I33 and I33 to permit locking of the head. '80, these elements are correctlytermed non-locking ones in that they do notlock the head in threading position.

Poi-theme! munlthellid1ockihl' ring I33, I have provided a handle 3 which is threaded into said ring I" and whose reduced hand, when the head is opened,-

end 2 coacts with a keyway 2|: formed in the shank member 23. The keyway.2l2 extends a sumcient peripheral distance so as not to interfere with the rotation of the locking ring I50; however, it does limit the range of rotation thereof. It i evident that a cam (not shown) could be employed to reset the die head automatically by eflecting the proper rotation of the handle If it should be desired to trip the die head manually instead of relying on the pull-off action, to facilitate such tripping, I have provided the latch members I45 with camming surfaces 2 which are designed to coact with the peripheral latch surfaces I90 of shank 23 and which also are further inclined therewith in a second plane so that relative rotation between the locking ring and the shank result in a substantial radially outward movement of the said latches. I45 (see Fig. 4) Thus, it is not necessary to attempt to manually open the die head solely by 'forcing the front unit thereof forwardly, for a minor rotation of the handle 2I0 effects a major outward displacement of the latches and very little additional effort is required to pull the front unit of the head sufficiently forward to effect a collapsing of the chasers. Again, it is clearly evident that an auxiliary cam (not shown) could be used to actuate the handle instead of manually so doing. As can be appre- :iated, this constitutes an important safety fea ure.

From the foregoing description of my die head,

producing relative axial displacement of rings.

4. A head for mounting a thread-cutting tool having a'shank member provided with latch actuating surfaces, a locking ring, one or more radially' slidable latch members mounted in said locking ring, said latch members being provided with complementary camming surfaces adapted to be. actuated-by camming contact with said respective latch actuating surfaces.

5.. A two unit head for mounting a thread-cutting tool comprising a front unit including a body member, a. closing ring, an adjusting ring, and a locking ring, and a rear unit including ashank member and a retaining ring; said shank mem-' her having latch activating surfaces thereon, a plurality of mutually coacting non-locking camming means located in said closing and locking rings'and adapted to effect axial displacement thereof radially slidable latch members mounted in saidllocking ring and adapted to be actuated by virtue of their camming contact with said respective latch actuating surfacesformed on said shank member.

6. A head for mounting a thread-cutting tool as is set forth in claim 1; said mutually coacting non-locking camming means comprising a coneit will be evident that I have accomplished my original objectives, and have produced a pulloif type die head whose features are comparable to those'of the yoke actuated type die head disclosed in my co-pending application; Serial No.

268,966 and which has additional important fea- -tures only inherent therein. 4

It will be obvious to those skilled in the art that various changes may be made in this device without departingfrom the spirit of the invention and therefore the invention isnot limited to what is shown in the drawings and described in the specification but only a indicated in the appended claims.

What is claimed is: 1 1. A two unit head for mounting a thread-cutting tool'comprising a front unit including a body member, a closing ring, an adjusting ring, and a locking ring, and a rear unit including a shank member and a retaining ring: said closing ring and said locking .ring having mutually coacting "55 member and a retaining ring: said shank memresiliently pressing said radially slidable latchmembers into engagement'with said latch actur ber having latch actuating surfaces and said locking ring having radially slidable therein-a plurality of latch members having complementary camming surfaces adapted tobe actuated by virtue of their camming contact with respective' latch actuating surface formed on said shank member.

3. Ahead for mounting a thread-cutting toolcomprising a closing ring and a locking ring axiaily displaceable one relative to the other, and mutually coacting non-locking camming means headed pin locatedin one of said rings and cooperating with a'countersunk camming surface formed in the other of said rings. 1

'7. A head for mounting a three. -cutting tool as is set forth in claim 5; said mut lly coacting ing non-locking camming means comprising a plurality of cone-headed pins located in said closing ring and having respective camming contacts with aplurality of countersunk cammingv surfaces formedin said locking ring; means for ating surfaces ofsaid shank member.

8. A head for mountings threadecutting tool. 4

including a locking ring, radially slidable latch members mounted in said locking ring and hav-' ing camming surfaces coacting with cooperating camming surfaces on another member of the head, the camming contacts being both inclined with respect to and spiralling away from the longitudinal axi of the head-whereby said latch members are actuated by both relative axial displacement and relative rotational displacement between said locking ring and said other member of the head.

9. In a two unit head for mounting a threadcutting tool; radially slidable latch members mounted in one of the two units-of the head, latch actuating surfaces in the other unit of the head, said latch members each having an inclined spiral camming contact with said latch actuating surfaces, whereby either relative axial displacement or relative rotationaldisplacement between said two units of the head will actuate said latches radially. Y Y 7 10. A die head having a shank member provided with a circumferential, keyway, a closing ring, a. locking ring, radially slidable latch members carried by said'locking means, said closin ring and said locking ringhaving mutually coacting non-locking camming means for. axially displacing said radially slidable latch members relative to said'closing means, means for limit-' comprising a handle mounted in said locking ring and having limited peripheral movement within" disposed in said rings and of a configuration for. the of 'said circumferentialfkeyway.

as is set forthin claim 5: said closing ring of said assembly having an uninterrupted annular latch coacting surface which forms a locking seat for the latching surfaces of said radially slidable latch members.

13. A head for mounting a thread cutting tool as set forth in claim 5; said closing ring of said assembly having an uninterrupted annular latch coacting surface to form a locking seat for the latching surfaces of said radially slidable latch members and further having an annular recess concentric therewith and adapted to receive the latch abutments of said latch members a the head is tripped; said annular recess of said closing ring being independent of any head resetting fimctions.

ing ring movably cooperating with said closing ring for operating the closing ring to thread cutting locked position and permitting it to move to unlocked or released position to open the chaser holders and chasers and further cooperating with a shankmember provided to drive said body member inv that a plurality of radially slidable latch members are mounted therein and are adapted to be actuated by having camming contact with respective latch actuating surfaces formed on said shank member, opening springs positioned between the body member and closing ring to provide means for forcing the closing ring to its open or release position when the locking ring has been moved to a position permitting the chasers to open, and an adjusting ring'connecting the body member and locking ring to hold the die head members assembled and permit adjustment to vary the diameter of the threads cut by the chasers.

17. A die head comprising a body member having radially movable tangential chasersflln axially movable member for moving the chasers ra- 14. A die head comprising a member, a

shank member, a plurality of chaser holders slidably mounted on one end of said body member, tangential chasers mounted on said holders, closing and locking rings mounted on said body member, and an adjusting ring connected to the body member and extending over said closing ring and connected to said locking ring with a bearing engagement to hold the said rings assembled onthe body member, said locking ring having radially slidable latch members mounted therein and adapted to be actuated by virtue of their camming contact with respective latch actuating surfaces formed on said shank member which is provided to drive said head body.

head face, springs within said enlarged head to force said closing ring rearwardly with "respectto the chasers, a locking ring behind closing ring. cone-headed pins located in of said rings and coacting with countersunk surfaces provided in the other of said to eifect forward movement of the said 16. Adieheadcomprisingabodymember hav-. ing chaser holders and tangential chasers slidabiy mounted thereon, a closing ring mounted for axial movement on the body member and cooperating with the chaser holders to move them radially in and out on the body member,'a lockadiusting rins extending from dially into and out of thread cutting positions, a locking member cooperating therewith for effecting the movement of the chasers to a locked thread cutting position, spring means between said chaser moving member and the die head body member for eflecting a retracting movement of the. chasers to released or non-thread cutting position, an adjusting ring connecting said body member withsaid locking member and enclosing said chaser moving means, a supporting member upon which said body member is axially movable, yieldable connecting means between said locking member and said supporting member retaining said body member thereon and permitting a forward movement thereof, and radially slidable latching means mounted in said locking member and having camming surfaces contacting with latch actuating surfaces on said supporting member to effect a movement of the chasers to released position upon such forward movement of the head body.

18. A die head comprising a body member having radially movable tangential chasers and chaser moving members, a rear supporting unit therefor comprising a shank with a collar thereon inward of its front end, means for mount a-die headsoastomove axially onsaidshank.

forwardly of said collar, a retaining ring on said shank in cooperative engagement with said collar, yieldable connecting means between said re-- taining ring and said die, head members permitting the die head to move forwardly on the front end of the sh'ankmember, and means co-operating with thechaser moving membersto eifect anopening of the chasers when the body portion of the die head moves forwardly on said supp rting member, said means comprising radially slidable latch members having camming surfaces contacting with latch actuating surfaces formed on said 19. In a thread cutting die head a front unit, a rear unit. thread cutting means on said front unit movable between closed and open podtions, "means for-locking said thread cutting means in closed cutting position, means connecting said front and rear units to provide a. positive drive therebetween. and' cooperating retaining ring and stop means onsaid front and rear unite lim-.

iting the movement of the front unitforwardly of said rear unit, said connecting means permitting the front unit to move forwardly of the rear' unit without disturbing said positive drive or the locking action of the cutters, said means for locking said thread cutting means comprising radially slidable spring pressed latches located in said front unit and having axial androtative camming contact with coacting latch actuating surfaces located in said rear unit or said die head.

means for axially displacing said closing ring relave to said locking ring, means for limiting the tal permissible rotation of said locking ring relafive to said shank member, said limiting. means including a handle mounted in said locking ring and having limited peripheral movement within the confines of said circumferential key- I way.

21. The combination set forth in claim 20, wherein said radially slidable latch members are adapted to coact with said latch camming surfaces of said shank and with said limiting means to restrain said locking ring from appreciable clockwise or counter-clockwise rotation.

w CHARLES A. REIMSCHISSEL. 

